Banding but not in lightroom

• Pitmatic

  Member

  January 16, 2011 at 10:40 pm

  Now this image in Lightroom 3 looks fine (on my monitor anyway…) but load it into ps5 and thre is a fairly obvious banding effect coming from top right

  Is it me or am i going mad(der) :) and i have no idea what it is it was in a potpourii selection

  
  miki g

  Participant

  January 16, 2011 at 11:44 pm

  Don’t know why you have banding in PS5 & not in lightroom. I get banding occasionally in Paintshop & it is usually due from going from dark to light areas in the shot (or vice versa). I can usually fix it by altering the Highlight, midtones & shadow values or the brightness & contrast. I think it may be because the exposure is wrong (either over or under exposed slightly) & don’t think it’s the monitor that’s the problem.
  jaybee

  Participant

  January 17, 2011 at 9:12 am

  what bit depth is the image in, and does the banding dissappear at different zoom levels…

  I know older versions of ps had issues displaying all of the info available in 12-bit images at some zoom levels (I believe its a corrollory of moire effect)

  I have the same issue with a really dark sky in an image from joshua tree but when printed its perfect…
  Pitmatic

  Member

  January 17, 2011 at 11:16 pm

  well ill be i tried zooming to 66% and up and the banding vanishes…

  the image is 14 bit from a d700 and is processed in ps 16 bit mode obviously the jpeg is 8 bit so i was confused by photoshop doing the this ho hum will now relax and learn to not worry about it :)
  jaybee

  Participant

  January 19, 2011 at 10:47 am

  its good to worry, but nice to find out it was all unneccessary!! PS does some crazy stuff, in CS if you performned two “calculations” in a row in 16-bit it would generate a perfect chequerboard pattern!!
  iophotoworks

  Participant

  January 22, 2011 at 7:37 pm

  The internal working space in Lightroom is ‘Pro Photo’, 16bpc. This is not entirely obvious in the Lightroom UI.
  The reason that Adobe use this internally is that Pro Photo has a huge colour gamut and 16 bits gives you enough levels to not only contain a 10, 12 or 14 bit RAW file but also it allows some heavy post-processing without pushing colours out of gamut or introducing posterization or banding.

  If you set your workflow options in Camera RAW as well as the ‘Colour Settings’ in Photoshop to match the internal LR environment (Pro Photo 16bbc) you may possibly avoid the banding you are seeing. However, if for example ACR and Photoshop were set to 8-bit and Adobe RGB (and I see this all the time on clients computers) then you would not have as much editing flexibility as in Lightroom and the likelihood of introducing banding is higher.

  Please note especially that Pro Photo and 8-bit is a very dangerous combination as you have a huge gamut with only 255 levels per channel so the chances of seeing or introducing posterization and banding with that combo are quite high. If you choose to use the power of Pro Photo then you really need to work in 16-bit bit-depth all the way through.

  Also note that when you export to put things on the web then you are usually chopping the file down to 8-bit JPEG, sRGB and thus banding may be introduced at that point.

  Hope this is helpful and makes some sense.
  Pitmatic

  Member

  January 23, 2011 at 11:28 am

  Thanks tony

  I am always exporting to PS in prophoto with 16bit colour depth so that should be the optimal settings?

  I have noticed banding can be introduced by the blur filters but i came accross an article on the internet that explained how to fix it (hide it whatever…)

  add a new layer with blend mode set to overlay and fill with overlays neutral 50% grey and then add noise with the noise filter of about 2% – 3% and this is quite good at fixing the banding at 100% although i cant guarantee that it would work for everyone.